Re: [PATCH v2 2/6] ebpf: Added eBPF initialization by fds.

[Daniel P . Berrangé]

On Fri, May 12, 2023 at 03:28:58PM +0300, Andrew Melnychenko wrote:
> It allows using file descriptors of eBPF provided
> outside of QEMU.
> QEMU may be run without capabilities for eBPF and run
> RSS program provided by management tool(g.e. libvirt).
> 
> Signed-off-by: Andrew Melnychenko 
> ---
>  ebpf/ebpf_rss-stub.c |  6 ++
>  ebpf/ebpf_rss.c  | 27 +++
>  ebpf/ebpf_rss.h  |  5 +
>  3 files changed, 38 insertions(+)

Reviewed-by: Daniel P. Berrangé 


With regards,
Daniel
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[PATCH v2 2/6] ebpf: Added eBPF initialization by fds.

[Andrew Melnychenko]

It allows using file descriptors of eBPF provided
outside of QEMU.
QEMU may be run without capabilities for eBPF and run
RSS program provided by management tool(g.e. libvirt).

Signed-off-by: Andrew Melnychenko 
---
 ebpf/ebpf_rss-stub.c |  6 ++
 ebpf/ebpf_rss.c  | 27 +++
 ebpf/ebpf_rss.h  |  5 +
 3 files changed, 38 insertions(+)

diff --git a/ebpf/ebpf_rss-stub.c b/ebpf/ebpf_rss-stub.c
index e71e229190d..8d7fae2ad92 100644
--- a/ebpf/ebpf_rss-stub.c
+++ b/ebpf/ebpf_rss-stub.c
@@ -28,6 +28,12 @@ bool ebpf_rss_load(struct EBPFRSSContext *ctx)
 return false;
 }
 
+bool ebpf_rss_load_fds(struct EBPFRSSContext *ctx, int program_fd,
+   int config_fd, int toeplitz_fd, int table_fd)
+{
+return false;
+}
+
 bool ebpf_rss_set_all(struct EBPFRSSContext *ctx, struct EBPFRSSConfig *config,
   uint16_t *indirections_table, uint8_t *toeplitz_key)
 {
diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
index 247f5eee1b6..24bc6cc409e 100644
--- a/ebpf/ebpf_rss.c
+++ b/ebpf/ebpf_rss.c
@@ -146,6 +146,33 @@ error:
 return false;
 }
 
+bool ebpf_rss_load_fds(struct EBPFRSSContext *ctx, int program_fd,
+   int config_fd, int toeplitz_fd, int table_fd)
+{
+if (ctx == NULL || ebpf_rss_is_loaded(ctx)) {
+return false;
+}
+
+if (program_fd < 0 || config_fd < 0 || toeplitz_fd < 0 || table_fd < 0) {
+return false;
+}
+
+ctx->program_fd = program_fd;
+ctx->map_configuration = config_fd;
+ctx->map_toeplitz_key = toeplitz_fd;
+ctx->map_indirections_table = table_fd;
+
+if (!ebpf_rss_mmap(ctx)) {
+ctx->program_fd = -1;
+ctx->map_configuration = -1;
+ctx->map_toeplitz_key = -1;
+ctx->map_indirections_table = -1;
+return false;
+}
+
+return true;
+}
+
 static bool ebpf_rss_set_config(struct EBPFRSSContext *ctx,
 struct EBPFRSSConfig *config)
 {
diff --git a/ebpf/ebpf_rss.h b/ebpf/ebpf_rss.h
index ab08a7266d0..239242b0d26 100644
--- a/ebpf/ebpf_rss.h
+++ b/ebpf/ebpf_rss.h
@@ -14,6 +14,8 @@
 #ifndef QEMU_EBPF_RSS_H
 #define QEMU_EBPF_RSS_H
 
+#define EBPF_RSS_MAX_FDS 4
+
 struct EBPFRSSContext {
 void *obj;
 int program_fd;
@@ -41,6 +43,9 @@ bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx);
 
 bool ebpf_rss_load(struct EBPFRSSContext *ctx);
 
+bool ebpf_rss_load_fds(struct EBPFRSSContext *ctx, int program_fd,
+   int config_fd, int toeplitz_fd, int table_fd);
+
 bool ebpf_rss_set_all(struct EBPFRSSContext *ctx, struct EBPFRSSConfig *config,
   uint16_t *indirections_table, uint8_t *toeplitz_key);
 
-- 
2.39.1